Garrett, 33, grew up on a dairy farm in the rural countryside of southern Texas, and her first job as a young girl was starting a roadside flower stand. She handpicked the flowers from the field, and sat at her stand trying to sell flowers to anyone who would pass by. At 14, she started buying and selling cattle. When she was 21, Garrett postponed her collegiate studies to take a leap of faith with her then-fiancé into day-spa services.

Garrett opened her first spa in her hometown of Victoria, Texas, in 2001. Three years later, she started franchising the concept and has grown the franchise to more than 29 spas in 14 states.

Another 12 franchises are expected to open in the U.S. this year. And Garrett aims to add at least 125 domestic locations over the next five years.

The Woodhouse Day Spa is also expanding internationally, with plans to open its first location in India this year and a signed master franchise agreement there for the development of 100 locations over 10 years. She's also looking to Canada and Mexico for expansion.

Garrett spoke to us about the challenges of starting a business so young and how The Woodhouse Day Spa is standing out in the $13 billion U.S. spa industry.

Why did you decide to open a spa and how you were able to run it at such a young age? You must have had a lot of confidence, because when I was 21, the last thing I was thinking about was starting a business.

Garrett: Well, I'm not sure I did have a lot of confidence back then, but I've always loved spas. My mom and I would travel to Houston to go together on Mother's Day and special occasions. I just fell in love with it at a young age. They were all very mysterious to me back then because there weren't a lot of day spas around. Years later I had the opportunity when a friend of mine -- she's now our director of operations and has been for the last 10 years -- was traveling with me to Houston to go visit a day spa, the thought popped in my head, and I said, 'We need one of these in Victoria, our hometown.' That was on a Friday and on that Monday, my fiancé at the time and I bought a house. Twenty-nine weeks later, we opened our first Woodhouse Spa.

Garrett: I'm an entrepreneur at heart. Victoria, Texas, was an experience-starved society and there was not a lot of competition 12 years ago, and I knew that. I just had an instinct -- a marketing instinct that we could market this, and that we could create a demand for these gift cards and make this a sustainable business model. And, again, I was young. I was confident. I went into it with probably less planning than most people would these days. It was 12 years ago, so I didn't spend a whole lot of time on Google ( GOOG). These days I would probably be paralyzed by research. I wasn't back then. I think that all of those things helped me.

Being so young, what experience did you have to be able to run a company like this?

Garrett: At the age of 12, my sister got me involved in doctors' offices doing worker's comp. claims. So I started at a very young age working summers. I started my own business selling flowers and had a little cattle company. I had a little jewelry business. My mom and I would travel back and forth to Dallas to a market where I sold jewelry and clothing, and so I had that business experience and then I also became the business manager for a chain of ambulatory surgery centers where I developed a cost-accounting system. They liked it so much that I was able to travel and implement it into their different locations, and so that experience helped me a lot to bring that into our model. So all of that experience, all of those little things I picked up along the way, gave me the confidence that I knew I would be able to do this.

What were some of the concerns that you had as a young female CEO? Was there a fear of being disrespected?

Garrett: I think that some of the earlier challenges were when we would go to get financing -- explaining to these male bankers what was a day spa. Back then, they had no idea what a day spa was and so to explain that was a challenge. Then getting into the franchising world, which was predominantly male-dominated, was a bit of a challenge, but I never felt as if my age or the fact that I was a young female hindered me . I was extremely focused and worked very hard for a long time.

When we started the franchise, the way that happened, I had some people come to us early on and when the business was going so well they would say, 'I really love this business. Would you be interested in franchising?' I always knew that we wanted to expand The Woodhouse, but I didn't know what method, whether it was going to be company-owned or franchises. And so I started looking into franchising, and I fell in love with that model because the day-spa industry is so employee-heavy, and grass-roots marketing is so important. So you really need an owner/operator in that market encouraging your team and marketing there.

So let's talk a little bit about the growth trajectory. First of all, are consumers today willing to pay for spa services?

Garrett: We had 20% comp sales growth in 2012, so compared to the national retail average of comp sales, it's 'yes.' I think the reason is -- and I can back up and tell you we opened our first location two weeks after 9/11 -- history and time has shown that consumers look to our spas during these times for stress-relief. Our spas are extremely busy right now because we have positioned ourselves as an affordable luxury and we've priced ourselves very well in the market to where consumers can afford to come monthly to The Woodhouse. They're coming and they're coming back often.

What are the plans for expansion?

Garrett: The way that we are growing right now is through what's called regional development. We've broken the U.S. into 60 regions and each of those regions will be represented by a regional developer. Right now we have around 86 contracts for spas to be developed over the next 10 years. So, domestically, that's how we plan to grow. Internationally, we have 90 locations under contract to open in India over the next 10 years. The first location will open this year. It's a 15,000-square-foot wellness spa. Then there are four more leases that are signed for additional locations.

Why is there opportunity internationally and, specifically, why are you expanding in India?

Garrett: Everybody asks me, 'Why India?' A lot of franchisors choose based upon the demand and the location. We went with the person and the relationship. I had known the developer in India now going on seven years. She is a wonderful person and she's from the States, but her family is in India. She has a background in hotel development and really strong hospitality training. She fell in love with The Woodhouse. We've worked together for a long time on this idea of her taking The Woodhouse to India. We had spent the last 10 years building the foundation, the support, all of the things to get us ready for growth. We were ready at the time when she came along to support her with that and so that's kind of how that happened.

What challenges are there to franchising internationally?

Garrett: There are many challenges internationally, and the cultural changes are one of the larger ones. We've learned that we had to adjust our menu somewhat. An example of that is there's a lot of diabetics in the area that we're going into, so we're adjusting our menu to offer more wellness programs that are related to helping diabetic guests.

Logistically, we have to adjust our systems because of the currency. So there are challenges there. And the communications, of course. There are major time differences with India, so your team has to be ready to do the support calls at different times a day.

Are you looking to go into other countries?

Garrett: We're working with someone in Canada. We have a contract for Mexico but we are waiting on some things to clear up down there. We are open to other areas as well.

That said, we're really focused on domestic growth right now.

What's the best piece of business advice you've received?

Garrett: I can share just from my own mistakes that I've made. I've learned to listen to my advisers, my people, whether that's my board or my franchisees or even my home team, as we call it, my staff here. I've become a much better listener, rather than just going with my ideas first. So that's probably been a number one lesson I've learned is to listen more and speak less.

Listening is the big one and then giving your employees more ability to make decisions on their own, so that you can focus on the big picture and growth. So I think that's probably the two lessons I've learned.